The gasket is around £ 5 - 10 from the main dealers. i its a matter of 3 torx headed bolts that go through the manifold. and a bolt which goes through a bracket underneath, should be able to remove these bolts and move the turbo down slightly, just enough to get the gasket put the new one in and put the bolts back through. have to remove the charge pipe and a few bits on top to get to the bolts easily.
labour at our garage we would charge max maybe around £ 50.
the bolts in the turbo can be a nightmare thou sometimes probably because of the heat they get solid in the studs, also the studs cant be brought from the main dealer seperate so have to be made at a tapping/threaded inserts specialists. alot of people have had this
problem and means you have to remove the turbo in some cases which is a few hours properly.